Small-Angle Neutron Scattering: Applications to Multi-Component Systems Sarah Rogers ISIS Facility, Rutherford Appleton Laboratory, UK Neutrons for Science Neutrons Where atoms are... Neutrons ...and what they do Neutron Properties Neutron Properties H Li C O S X -rays neutrons Mn Zr Cs Neutron Properties H Li C O S X -rays neutrons Mn Zr Cs Spallation Neutrons Accelerator Driven Neutron Source (Spallation) Accelerator Driven Neutron Source (Spallation) Target 2 High Energy Protons Target 1 excited nucleus 15-20 neutrons High energy Proton The collision of high energy protons with the tungsten nuclei releases neutrons Moderators β ππ = ππππ epi-thermal Spallation 109 Energy (eV) 106 103 10-5 ππ = 293πΎπΎ cold ultra-cold 100 10-3 10-6 Electronic transitions Molecular vibrations Sound modes Diffusion Excitations Polymers and bio-molecules Lattice spacing Wavelength (nm) 10-6 hot thermal 10-4 10-3 ππ = 1.798 β« 10-2 10-1 π£π£ = 2.20 ππππ/π π Structure 100 101 πΈπΈ = 25.3 ππππππ 102 L1 L2 Sample 2ΞΈ Neutron Source Distance Neutron Detector Time-of-flight πΈπΈ = Time π£π£ = πΏπΏ1 + πΏπΏ2 βπ‘π‘ 1 πππ£π£ 2 2 ππ = β ππππ ππππ = 2ππ sin ππ Inelastic Scattering Scattering: Reciprocal Space Dynamical Behaviour Structure: Real Space Spectroscopy Molecular Spectroscopy IRIS OSIRIS TOSCA VESUVIO MAPS LET MARI MERLIN HET Engineering Large Scale Structures ENGIN-X SANS2D Diffraction OFFSPEC HRPD POLREF SXD INTER POLARIS CRISP GEM SURF Neutron and Muons WISH LOQ Instruments PEARL INES 30 Muons EMU MuSR HIFI ARGUS Disordered Materials SANDALS NIMROD Target Station 2 β Phase 2 Instruments IMAT ZOOM LARMOR CHIPIR World leading expertise and instrumentation in the application of neutrons to condensed matter science ~ 2000 users/yr ~450 publications/yr ~ 800 experiments/yr 90% of UK Users 5/5* Departments Access Mechanisms Direct access Rapid access Xpress Programme access Commercial ICRD scheme Neutron & Nanometers Small-Angle Neutron Scattering (SANS) Lengthscales probed range from 10s to 100s nm. They are explored in reciprocal space by detecting the number of scattered neutrons as a function of the scattering vector, Q. Q is inversely proportional to distance, D, by the approximation: Detector Incident beam, wavelength l q Sample Allows the bulk properties of a material: β’ Size β’ Polydispersity β’ Structure β’ Particle Interaction 2ππ π·π· Units are either Å-1 or nm-1 i.e. the smaller the value of Q the bigger the object Scattered beam Scattering vector, Q ππ = Transmitted beam Q is also related to wavelength and the scattering angle by: ππ = 4ππ sin ππ ππ 2 Q (size) range is varied by altering q or l βTypicalβ Experiment The 2D SANS patterns obtained are often radially averaged to given an βintensityβ, I(Q), vs. Q plot 2D Radially average 1D Modelling I(Q) contains the information on size, shape and interactions between the scattering centres in the sample. For monodisperse spheres I(Q) can be defined as: πΌπΌ ππ = Οππ β ππππ 2ππππππ ππ2ππ ππ ππ ππ + B Form factor: intra-particle information - size and shape of particle Structure factor: inter-particle information. Depends on the type of interactions in the system. S(Q) = 1 for dilute dispersions βFlat backgroundβ. Generally regarded as due to βincoherentβ scattering, often due to hydrogen The 1st - Loq β’ LOQ was the 1st ISIS SANS instrument and is positioned on the 50 Hz first target station, TS-1 β’ This instrument has demonstrated the power of SANS at a pulsed source β’ Using a fixed sample - main detector distance of 4 m and neutron wavelengths of 2 to 10 Å at 25 Hz a Q-range of 0.007 β 0.3 Å-1 is accessible β’ This Q-range can be extended to 1.4 Å-1 by employing the wide-angle detector bank β’ Extensive sample environments available β’ Sample area is the βpitβ which is accessible via a ladder β’ Crane available For further info contact Steve King: [email protected] Monit or 3 (only placed in beam f or t ransmission measurement s Area det ect or Monit or 2 Frame overlap mirrors High-angle det ect or bank Sample Monit or 1 Apert ure select or 2 Double-disc chopper NEUTRONS 25K liquid hydrogen moderat or Apert ure select or 1 Soller supermirror bender The present - Sans2d β’ Sans2d is the first SANS instrument to be built on the optimized TS-2 β’ Operational since 2009 β’ Detector 1 moves +/- 0.3 m sideways, to 12 m from sample. Detector 2 may be offset to 1.4 m sideways in 3.25 m diam vacuum tank and rotates to face sample β’ Combining the low background and high flux of Sans2d has allowed weakly scattering samples to be studied more efficiently β’ Crane available β shared with Zoom For further info contact Sarah Rogers: [email protected] 100 I(Q) / cm-1 β’ 2 x 1m2 movable detectors provide a uniquely wide simultaneous Q range at good resolution: Q = 0.001 to 3 Å-1, Ξ» = 1.75 to 17 Å Scattering from partially deuterated polymer shows good overlap between Sans2d and Nimrod Sans2d NIMROD 10 1 0.1 0.001 0.01 0.1 1 10 Q / Å-1 100 Larmor: Flexible Spin-Echo for Larmor Precession β’ Shutter opened on 20th March 2014 β’ SANS is available now. The spin-echo setup is being developed with the NWO and TU-Delft over the next year β’ Polarized Beam with Analysis β’ Wavelengths 0.5 β 13 Å gives SANS Q range of 0.004 1.6 Å-1 β’ Length scales of ~20 nm to 20 mm can be studied using SESANS β’ Large block house but detector can move 90° on air pads β’ Huber sample stack allows for accurate sample alignment β’ Crane available For further info contact Rob Dalgliesh: [email protected] Future 2 - Zoom β’ Currently under construction β’ Planned open shutter date is November 2016 β’ SANS will be available from day 1. Polarized and focusing SANS will be delivered later β’ Detector can move to 6 or 9 m from sample β’ Vacuum tank can also move 3 m for focusing optics installation β’ Wavelengths 1.75 β 16.5 Å gives Q range of 0.002 - 1 Å-1 β’ Focusing will allow ultra low Q of 0.0003 Å-1 ~ 2 mm β’ Huber sample stack allows for accurate sample alignment β’ Crane available β shared with Sans2d For further information contact Ann Terry: [email protected] Polymers in solution for drug coatings Solution scattering Ionic liquid mixtures Growth of fibrils Orientation of peptide fibrils Anomalous relaxation behaviour in alcohol-water mixtures Hydrogen loading Surfactant stabilised carbon nanotubes Defects in metals Interfacial structures of polymers at various interfaces Nanoparticles in metal alloys Interaction of polymers with DNA Colloidal crystals Flux line lattices Foams Organic Light Emitting Diodes (OLEDS) Templating of nanoparticles with micelles and microemulsions SANS Exchange in nanoemulsions Interaction of perfume with micelles Carbon nanotubes Movement of drugs through and into vesicle bilayers Micellization in CO2 The Sample Environment Extensive available sample environments allow a broad range of science to be studied via SANS at ISIS. Sample environment includes: β’ Standard ISIS cryostats, furnaces and magnets β’ Sample changer with temperature control (a) β’ Linkham stages for advanced temperature control (b) I(Q) /cm-1 15 10 β’ Rheometer and shear cells time 5 β’ Pressure cell β 600 bar with stirring. Predominantly used with CO2 β’ T-jump cell β study non-equilibrium phases β’ In-situ DLS and UV-vis β’ Grazing Incidence SANS (GISANS) 0 ai + af Incident beam ai Stopped-flow β mixing kinetics β’ Well equipped offline labs allow for further characterization Ø X-ray sets, AFM, BAM, spectrometers 0.04 0.08 0.12 Q /Å-1 Specular peak af Yoneda Maximum Transmitted beam Ø Study of in-plane structure on the nm lengthscale β’ 1 mm 0 qy isotopes H Nuclear Interaction Changes D Li C O S X -rays neutrons Mn Zr Cs Collaboration between University of Bristol and the ISIS SANS team studying the modification of the physico-chemical properties of sc-CO2 with surfactants for use in enhanced oil recovery. Low viscosity of CO2 promotes fingering through porous media rather than a uniform sweep. Modifiers commonly used in oily solvents are incompatible with CO2. Can self assembled custom-made surfactants be used? Why Neutron and Small Angle Scattering? surfactant High penetrating power of neutrons allows a p-cell with thick windows to be employed Using D2O allows us to see βnanopoolsβ of water in the CO2 Length-scales being probed are ideal for SANS Na+ or Co2+ or Ni2+n(D2O) Results Altering the counterion of the CO2 active surfactant DHCF4 from Na to Ni or Co causes a viscosity enhancement of up to 90% compared to pure CO2 Why? Neutrons have the answer! Micelle shape changes from spherical to wormlike as counterion changes from Na+ to Co2+ or Ni2+ Langmuir 2010, 26(1), 83-88 Collaboration between Lund University and the ISIS LSS team studying reversed lipid liquid crystalline nanoparticles as drug delivery vehicles These systems are stabilised by low fractions of the surfactant P80. Location of the P80 within the particle largely control their function Why SAS? Neutrons are non-destructive so samples are not altered by beam damage Contrast variation can be used to highlight specific parts of the system Length-scales being probed are ideal for SAS NH3+ NH3+ NH3+ NH3+ OH OH OH O- Results SANS profiles with modelled contributions shown SANS reveals the core-shell structure of the d-P80 micelles Hydrogenated tail group DO O O O O w O LCNP CH3 O O w + x+ y+ z = 20 DO OD P80 micelle Deuterated head group diffraction peak Results CV-SANS, CV-NR and SAXS have been used to determine a detailed picture of the internal structure of the LCNPs, where the P80 is located within these structures and how the particles are stabilised SANS profiles in P80 micelles in H2O (red) and 1:1 H2O:D2O (blue) Soft Matter 2015, 11, 1140 Work carried out by Infineum studying engine oil additives which consist of calcium carbonate nanoparticles β CaCO3 - stabilized by a sulfonate surfactant. The stability of these particles is crucial for their correct performance. The combustion process can produce a considerable amount of water: how does the presence of water effect these particles? CaCO3 Why Neutron and Small Angle Scattering? H/D Contrast provides direct view of water Length-scales being probes are ideal for SANS Ca(OH) layer Surfactant Results CaCO3 particles are spherical with dia. ~5.6nm Surfactant monolayer is of thickness ~1.8nm Water layer inserts between the calcium cation at the surface of the particle and the sufonate anion 1.8nm 5.6nm Langmuir 2008, 24, 3807 - 3813 Water 0.5nm Collaboration between University of Sheffield and the ISIS SANS Team studying transient phases in polymer crystallisation using a temperature jump (T-jump) cell designed for SAS beamlines. Polymer crystallisation is a highly non-equilibrium process and several different lamellar structures are possible Why SANS? SAS is a powerful technique for studying lamellar structures Using selectively deuterated segments, SANS can provide information on the location and state of order of such segments Sample sits here for ambient conditions Neutrons Sample is moved to the heated block for the SANS measurement Results Material C12D25C192H384CHDC11D23 used Lamellar structures possible are (a) extended chain form, (b) once-folded chain forn, (c) triple-layer mixed foldedextended (FE) form and (d) alternative models for the noninteger folded (NIF) form Results NIF form has a lifetime of ~ 1minute β time resolution achievable via SANS Real-time SANS βsnap shotsβ reveal structural changes with time and temperature Macromolecules 2005, 38, 7201 - 7204 Thanks for listening! Questions?
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